VALVES AND VALVE SPRINGS
5-18
EAS24280
REMOVING THE VALVES
The following procedure applies to all of the
valves and related components.
NOTE:
Before removing the internal parts of the cylinder
head (e.g., valves, valve springs, valve seats),
make sure the valves properly seal.
1. Check:
• Valve sealing
Leakage at the valve seat
→
Check the valve
face, valve seat, and valve seat width.
Refer to “CHECKING THE VALVE SEATS”
on page 5-20.
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a. Pour a clean solvent “a” into the intake and
exhaust ports.
b. Check that the valves properly seal.
NOTE:
There should be no leakage at the valve seat “1”.
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2. Remove:
• Valve cotters “1”
NOTE:
Remove the valve cotters by compressing the
valve spring with the valve spring compressor
and the valve spring compressor attachment “2”.
3. Remove:
• Upper spring seat “1”
• Valve spring “2”
• Valve “3”
• Valve stem seal “4”
• Lower spring seat “5”
NOTE:
Identify the position of each part very carefully so
that it can be reinstalled in its original place.
EAS24290
CHECKING THE VALVES AND VALVE
GUIDES
The following procedure applies to all of the
valves and valve guides.
1. Measure:
• Valve-stem-to-valve-guide clearance
Out of specification
→
Replace the valve
guide.
Valve spring compressor
90890-04019
YM-04019
Valve spring compressor attach-
ment
90890-04108
Valve spring compressor adapt-
er 22 mm
YM-04108
• Valve-stem-to-valve-guide clearance =
Valve guide inside diameter “a” -
Valve stem diameter “b”
2
1
YamahaR125.COM
Summary of Contents for YZF-R125
Page 1: ...5D7 F8197 E0 YAMAHAR125 COM SERVICE MANUAL YZF R125 ...
Page 6: ...YamahaR125 COM ...
Page 8: ...YamahaR125 COM ...
Page 52: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 29 1 2 3 4 YamahaR125 COM ...
Page 70: ...CABLE ROUTING 2 47 YamahaR125 COM ...
Page 73: ...YamahaR125 COM ...
Page 102: ...ELECTRICAL SYSTEM 3 29 YamahaR125 COM ...
Page 105: ...YamahaR125 COM ...
Page 172: ...CHAIN DRIVE 4 67 YamahaR125 COM ...
Page 181: ...ENGINE REMOVAL 5 6 2 2 4 1 3 YamahaR125 COM ...
Page 263: ...THROTTLE BODY 7 8 YamahaR125 COM ...
Page 264: ...AIR INDUCTION SYSTEM 7 9 EAS27040 AIR INDUCTION SYSTEM 1 2 3 YamahaR125 COM ...
Page 268: ...AIR INDUCTION SYSTEM 7 13 YamahaR125 COM ...
Page 271: ...YamahaR125 COM ...
Page 283: ...CHARGING SYSTEM 8 12 1 AC magneto 3 Rectifier regulator 4 Main fuse 9 Battery YamahaR125 COM ...
Page 285: ...CHARGING SYSTEM 8 14 YamahaR125 COM ...
Page 295: ...SIGNALING SYSTEM 8 24 YamahaR125 COM ...
Page 299: ...COOLING SYSTEM 8 28 YamahaR125 COM ...
Page 323: ...FUEL INJECTION SYSTEM 8 52 YamahaR125 COM ...
Page 327: ...FUEL PUMP SYSTEM 8 56 YamahaR125 COM ...
Page 353: ...YamahaR125 COM ...
Page 354: ...YamahaR125 COM ...